The molybdenum cofactor sulfurase ABA3 from Arabidopsis thaliana is needed for post-translational activation of aldehyde oxidase and xanthine dehydrogenase by transferring a sulfur atom to the desulfo-molybdenum cofactor of these enzymes. ABA3 is a two-domain protein consisting of an NH 2 -terminal NifS-like cysteine desulfurase domain and a C-terminal domain of yet undescribed function. The NH 2 -terminal domain of ABA3 decomposes L-cysteine to yield elemental sulfur, which subsequently is bound as persulfide to a conserved protein cysteinyl residue within this domain. In vivo, activation of aldehyde oxidase and xanthine dehydrogenase also depends on the function of the C-terminal domain, as can be concluded from the A. thaliana aba3/sir3-3 mutant. sir3-3 plants are strongly reduced in aldehyde oxidase and xanthine dehydrogenase activities due to a substitution of arginine 723 by a lysine within the C-terminal domain of the ABA3 protein. Here we present first evidence for the function of the C-terminal domain and show that molybdenum cofactor is bound to this domain with high affinity. Furthermore, cyanide-treated ABA3 C terminus was shown to release thiocyanate, indicating that the molybdenum cofactor bound to the C-terminal domain is present in the sulfurated form. Co-incubation of partially active aldehyde oxidase and xanthine dehydrogenase with ABA3 C terminus carrying sulfurated molybdenum cofactor resulted in stimulation of aldehyde oxidase and xanthine dehydrogenase activity. The data of this work suggest that the C-terminal domain of ABA3 might act as a scaffold protein where prebound desulfo-molybdenum cofactor is converted into sulfurated cofactor prior to activation of aldehyde oxidase and xanthine dehydrogenase.Molybdenum enzymes catalyze diverse redox reactions in the global carbon, nitrogen, and sulfur cycles (1). In all eukaryotic molybdenum enzymes, the molybdenum atom is coordinated by the dithiolene group of molybdopterin, thus forming the molybdenum cofactor (Moco) 2 (2). According to the coordination chemistry of the molybdenum ligand, eukaryotic molybdenum enzymes can be divided into two groups; Moco with two additional oxo-ligands and a protein-derived cysteinyl sulfur is bound by enzymes of the sulfite oxidase family, whereas enzymes of the xanthine oxidase family have one oxygen, one inorganic sulfur, and one hydroxyl group ligated to the pterin-chelated molybdenum of the active enzyme. Among the four different molybdenum enzymes known in higher plants, sulfite oxidase and nitrate reductase belong to the sulfite oxidase family, whereas aldehyde oxidase (AO) and xanthine dehydrogenase (XDH) are members of the xanthine oxidase family (3). Although it is believed that all of these molybdenum enzymes basically incorporate the same type of Moco, only AO and XDH, but not enzymes of the sulfite oxidase family, require a final enzyme-dependent post-translational modification of the molybdenum center for activity (4). During this modification step, an oxo-ligand of the Moco in inactive AO and XDH...

The breach in the dam of a tailing pond in the processing plant of a gold mine in Baia Mare (NW Romania) in January 2000 lead to an ecological disaster in the rivers Szamos and Tisza. It was mainly caused by the released slurries containing cyanides and heavy metals. The investigation of surface sediment samples and depth profiles of the years 2000 and 2001 documented the pollution of the rivers Szamos and Tisza on Hungarian territory. In the Szamos and large areas of the Tisza floodplains a significant enrichment with the heavy metals Pb, Cd, Cu, and Zn is existent. The identification of the binding forms with sequential extraction showed that Cd and Zn exist in an easily available form. Therefore the remobilization is possible and an environmental hazard in the downstream areas must be considered. The anthropogenically caused portions of heavy metal concentrations decrease considerably with increasing distance to the mining region. The comparison of the concentrations of heavy metals in both years shows that the pollution is not only caused by the accident in January 2000. The increase of concentrations is based on the permanent input of pollutants into the rivers. The pollution is mainly caused by the erosion of exposed tailing dumps and the poor maintenance of the treatment plants.

As improvements in neuroscience have enabled a better understanding of disorders of consciousness as well as methods to treat them, a hurdle that has become all too prevalent is the denial of coverage for treatment and rehabilitation services. In 2011, a settlement emerged from a Vermont District Court case, Jimmo v. Sebelius, which was brought to stop the use of an "improvement standard" that required tangible progress over an identifiable period of time for Medicare coverage of services. While the use of this standard can have deleterious effects on those with many chronic conditions, it is especially burdensome for those in the minimally conscious state (MCS), where improvements are unpredictable and often not manifested through repeatable overt behaviors. Though the focus of this paper is on the challenges of brain injury and the minimally conscious state, which an estimated 100,000 to 200,000 individuals suffer from in the United States, the post-Jimmo arguments presented can and should have a broad impact as envisioned by the plaintiffs who brought the case on behalf of multiple advocacy groups representing patients with a range of chronic care conditions.

This paper is programmatic: it defines the concept of “phantom borders” and describes its heuristic potential. The proposed approach positions itself between structuralist methodologies that postulate stable social and cultural regional structures and deconstructive viewpoints that reject the former, while focusing on the discursive dimension of regions. The paper takes this tension as its point of departure. Viewed from a situational perspective, phantom borders are neither to be understood as immutable structures nor as purely discursive constructions, but rather as an outcome of the interaction between three interwoven levels, which are simultaneously: 1) imagined in mental maps and discourses, 2) experienced and perceived by the respective actors, and 3) shaped by everyday practices and continuously updated and implemented. Phantom borders are context sensitive. We argue that the topic of phantom borders is not only relevant for research on eastern Europe, but also for research in “new area studies” in general.

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